Jack Barker is a mild-mannered software engineer by day, but at night he transforms into a lean, mean, robot-crushing machine.
The 25-year-old Auckland University graduate and his team of six are the new champions of Battlebots - a brutal combat sport where teams pit remote-control robots against each other in an arena-style fight to the death.
Filmed in California, the show has gained an international cult following, with tinkerers from across the globe all vying for a chance to win the Giant Nut.
For the last three years, Barker and his team have tried and failed to beat competitors with decades' more experience - past champions and expert mechanics who have been playing the game since 1995.
But this time none of them were prepared for End Game - 113kg of reinforced steel and pure nightmares from the minds of a group of brilliant young Kiwis.
At one metre wide and 60cm long, with a 20kg vertical spinner rotating at 400km/h, End Game rips apart its foes with the force of a speeding car hitting a brick wall.
"Everything is custom built, there's nothing you can just go out and buy," said Barker.
"Everything needs to be 10 times stronger than usual - or it breaks apart instantly."
While each match only lasts about two to three minutes, Barker's team were putting in 15-hour days back-to-back behind the scenes to repair the robot for the next fight.
"We have to take it apart after every fight, replace anything that's even slightly damaged, then rebuild the whole thing. We went through three robots' worth of parts, which cost about $67,000 all up."
Barker said the key to End Game's success came down to simple physics.
"Flipping or grabbing robots need to have perfect timing and precision - but End Game can quickly store a lot of momentum, then release that energy as soon as it makes contact, and it's pretty devastating."
While End Game's destructive force is nothing short of terrifying, one of the biggest challenges they faced was getting the robot to survive the impact without breaking apart.
"Having a vertical spinner means we can rely on the ground for support, whereas horizontal spinners have nothing to stabilise them, so they go flying when they make contact."
Barker has been a gearhead since age 3, when his father gave him a remote-control car - which he immediately took to pieces.
Years later he graduated with an engineering degree, went on to win multiple robot combat competitions in both Australia and China, before being invited to the set of Battlebots.
In October last year, Barker and his team braved Covid-19 and travelled to the US to partake in the show's 10th season, unaware they were about to claim the title.
The final match aired in New Zealand on March 11 on Discovery Channel.
None of Barker's previous achievements would compare to the moment when End Game blasted Californian-made Whiplash out of the arena.
"I was out of breath, almost crippled over. When it clicked we had won we all just screamed and grabbed each other.
"The thing I love most about robot fighting, is there are thousands of people out there all trying to do the same thing. It's similar to the America's Cup in that way - it's an engineering and piloting challenge where everyone has the same rules, you're just trying to do it better than anyone else."
Barker said next season they'll return to defend the Giant Nut, possibly with a lifting-arm type robot this time.
One thing's certain - carnage will ensue.